1. Field of the Invention
The present invention relates to an optical projection device and a projecting method thereof, and more particularly, to an optical projection device and a projecting method thereof utilizing a movable wave plate or a rotatable wave plate to equalize the laser energy and preventing interference speckle on screens.
2. Description of the Related Art
FIG. 1 is a schematic view of a conventional optical projection device. The conventional optical projection device 100 comprises a lens 11 and a laser engine 12. The laser engine 12 generates light 13. After passing through the lens 11, an image is projected on the screen 10.
However, in the conventional optical projection device 100, the path of light 13 from the laser engine 12 to the screen 10 is not changed. Thus, the interference position of light is not changed, that is, the interference speckle is also not changed. Thus, the interference speckle of the conventional optical projection device 100 is very conspicuous.